Air-brake system.



No. 869,837. PATENTED OCT. 29, 1907.

A. L. GOODKNIGHT.

AIB. BRAKE SYSTEM. v APPLIo-ATION FILED PBB. 16. 1907..

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ALVA L. GOODKNIGHT, OF COUNCIL BLUFFS, IOWA.

AIR-BRAKE SYSTEM.

Specification of Letters Patent.

Patented Oct. 29, 1907'.

Application filed February 15| 1907- Serial No. 357.765.

To all whom it may concern:

Be it known that I, ALvA L. GOODKNIGHT, a citizen of the United States,and a resident of Council Bluffs, in the county of Pottawattamie andState of Iowa, have invented certain new and useful Improvements inValves for Air-B rake Systems, of which the following is aspecification.

My invention relates to valves for fluid-pressurecontrolledrailway-brakes and it is the object thereof to provide a means forpreventing emergency applications of the brakes of an entire trainthrough defective operation of a triple-valve on a single car of thetrain. To set forth more clearly this object of my invention and conveya clear understanding of the operation of the means employed inattaining the same it is necessary to note in detail the nature of thedefective operation above referred to and its results on the brakemechanism of the train. In ordinary or service applications of thebrakes a gradual reduction of train-pipe-pressure is made at theengineers valve, the total reduction usuallybeing made in two or moreoperations thereof or, as it is said, the brakes are graduated on In theordinary triple-valves now in general use the valve will sometimes failto move and apply the brakes at the lhrst or second reduction oftrain-pipe-pressure, this failure to operate being caused by excessivepressure of the valve spring, or gumming or sticking of the valve, abroken graduating-spring or graduating-pin, or burs wearing in thepiston bushing. Such defective valves frequently, at the second or thirdreduction of trainpipe-pressure, will suddenly overcome the obstructionwhich has been causing them to fail to operate and, as a result of suchsudden movement, will pass to the emergency position, in sodoing causingthe opening of the emergency-valve venting train-pipe-air to thebrake-cylinder or atmosphere, the resulting sudden reduction oftrain-pipe-pressm'e throwing alll other triple-valves of the train intoemergency position. Thus a single defective triple-valve in a train maycause an emergency application of the brakes of the entire train, which,being undesired and unexpected by the engineer and being beyond hiscontrol, usually results in harmful strain of the draft rigging andcouplings of the train, and frequently causes serious breakage thereof.

My invention provides a simple and economical means, applicable to anyair-brake system now in general use, by which such defective action maybe confined to the defective valve itself and not transmitted to thebrakes of the entire train, at the same time permitting all properfunctions of the triple-valve to be performed in the usual manner.

A construction embodying my invention is shown in the accompanyingdrawings in which Figure l is a longitudinal sectionof the valve showingthe normal position thereof, which position is maintained at all timesexcept momentarily during a regular emergency application of the brakes,Fig. 2 is a similar view showing the position assumed by the valvemomentarily during an emergency application of the brakes, and Fig. 3 isa detail transverse section of the valve on the plane indicated by theline .t.t of Fig. l.

In the construction shown I provide a suitable casing l, having atopposite sides thereof the nipples 2 and 3 which are shown asexterior-ly and interiorly threaded, respectively7 adapting the same forconnection by ordinary pipe fittings with the proper portions of thebrake-system piping, Within the casing adjacent the nipple 2 is disposedthe vertically-movable cup-shaped check valve 4 which normally rests onthe inclined seat 5 formed in the casing, being held thereon by its ownWeight and the tension of the coil spring 6. Said spring 6 is placedaround the guide stem 7 which extends upwardly from the valve body intothe plug 8 which is screwed into the casing above the valve, as shown.The lower end of the plug 8 is counterbored at 9 to form a recess forcontaining the spring 6 when compressed and the valve in the raisedposition shown in Fig. 2. A small port l0 passes through the valve body4 from top to bottom thereof, as shown. Below the seat 5 is a dripchamber 1l having a plug l2 at the lowest point thereof. From thechamber ll a passage 13 extends upwardly to the nipple 3. When the valveis in the raised position shown in Fig. 2 a free passage is openedthrough the casing between the nipples 2 and 3, through the passage 13,chamber ll, valve seat 5, and the port I4 through the side of thecylindrical valve guide l5.

In the use of the valve for the purpose described the same is placed inthe branch-pipe leading from the train-pipe to the triple-valvemechanism, the connection from the nipple 2 leading to the train pipeand the connection from the nipple 3 leading to the triple-valvemechanism, the latter connection preferably being as short as possibleunder the conditions met with in practice.

In making service applications of the brakes in systems equipped asdescribed, the gradual reductions of train-pipe-pressure arecommunicated to the triplevalve mechanism through the small port l() inthe valve body 4, any moderate or gradual reduction oftrainpipe-pressure thus operating the brakes in the usual manner. Inmaking a regular emergency application of the brakes the suddenreduction of train-pipe pressure above the valve 4 cannot draw enoughair through the port 10 to reduce the pressure below the valve withsuicient rapidity to prevent said valve from being den reduction oftrain-pipe-pressure being thus com-y municated to the triple-valvemechanism the same is thrown to emergency position, the emergency-valveof the triple-valve mechanism is opened and train-pipeair vented to thebrake-cylinder or atmosphere in the usual manner. All these actions takeplace with eX- treme rapidity and, immediately following the initial`sudden reduction of train-pipe-pressure during which a flow ot` air isvmomentarily established through the branch-pipe and valve 4 from thetriple-valve mechanism toward the train-pipe, the flow thus establishedis reversed in direction and passes through the branch pipe and valve 4from the train-pipe toward the triplevalve mechanism, this furtherreduction ot' train-pipepressure affecting and being repeated. at eachtriplevalve mechanism of the entire train. At the time of the abovementioned reversal oi liow in the branch-pipe the valve 4 has beenraised by the first rush ot air toward the train-pipe, as described, andstands in the raised position shown in Fig. 2. Thus the valve has notendencyr to retard the rush of air toward the triplevalve mechanismafter the reversal oi flow through the branch-pipe, for the reason thatthe closing of the valve is retarded by such inward rush ol airsufficiently to prevent its closure before the said rush of air towardthe triple-valve mechanism is completed. The cupshaped form of the valveand theiarrangement of the port 14, by causing an eddying of the aircurrents below the valve, assists in retarding the closure of the valveuntil the desired action has occurred. Thus in either service oremergency applications et the brakes by the engineer the action of thetriple-valves in the usual manner is not interfered with in any way bymy valve mechanism.

Coming now to a consideration of the action of my valve in connectionwith a detective triple-valve it will be seen that, should the defectivetriple-valve during a service application of the brakes pass intoemergency position and vent train-pipe-air to the brakecylinder oratmosphere, the inward rush of air from the train-pipe to thetriple-valve mechanism can only take place through the small port l0,the valve il being closed and being openable only by sudden reduction ottrain-pipe-pressure, and such reduction not being made during serviceapplications of the brakes. Thus the only possible eiiect which thedefective triple-valve could produce on the other brake mechanism of thetrain is a slightly heavier service application ot the brakes caused bythe gradual reduction of train-pipepressure through the port 4, saidport being too small to permit a sudden reduction oftrain-pipe-pressin'e through the same, such as would be necessary tothrow the other triple-valves of the train into emergency position.

Now, having described my invention, what I claim and desire to secure byLetters Patent is:

1. The combination in and with a fluid-pressure-controlled railway-brakesystem, of means responsive to sudden reductions of trainfpipe-pressurein the emergency operation of the brakes for opening a large passagefrom the train-pipe to the triple-valve mechanism, and means forrestricting the Ilow ot train-pipeair into the triplevalve mechanismduring sei-vice operations of the brakes.

2. The combination in and with a iiuld-pressurecontrolled railway-brakesystem, o'f a valve arranged between the train-pipe and triple-valvemechanism, said valve normally restricting the passage between thetrain-pipe and triple-valve mechanism but being openable by suddenreduction of train-pipe-pressm'e.

3. ln a iluid-pressure-controlled railway-brake system, means torpreventing emergency reductions of train-pipepressure through defectiveoperation of a triple-valve, Said means comprising a valve arranged tonormally restrict the connection between the trainpipe and triple-va1vemechanism, said valve being openable only by emergency reductions oftraipipe-pressure.

4. ln an automatic air-brake system, a valve arranged between thetrain-pipe and triple-valve mechanism, said valve being open-able towardthe train-pipe, and there being a relatively small port affordingcommunication between the trainpipe and triple-valve mechanism when saidvalve is in closed position.

5. In an automatic air-brake system, a valve arranged between thetrain-pipe and triple-valve mechanism, said valve being openable towardthe train-pipe by sudden reduction of pressure therein, there being arelatively small port affording communication between the train-pipe andtriple-valve mechanism when the valve is in closed position, and meanswhereby when the valve is opened a rush of air from the train-pipetoward the triplewalve mechanism will retard closure of the valve.

6, 'ln an automatic air-brake system, a valve controlling communicationbetween the train-pipe and triple-vulve mechanism, said valve when openaffording a relatively large passage between the train pipe andtriple-valve mechanism and when closed restricting said passage, andmeans preventing `opening of said valve except by sudden reduction oftrain-pipe-pressure.

T. In an automatic-ai1brake system, a valve casing connected in thebranch-pipe between the train-pipe und triple-valve mechanism, aspring-impressed cup-shaped check'valve arranged within said casing andadapted when closed to restrict the passage of air through the same,said valve being openable by air pressure toward the train-pipe, andthere being a port arranged adjacent the valve where by when the valveis open a rush of air from the train-pipe will retard closure thereof.

In testimony whereof I have hereunto subscribed my name in the presenceof two witnesses.

ALVA L. GOODKNIGHT.

Witnesses D. O. BAnNnLr., JOHN ll. Summit.

